The Einstein 750 Headlamp by NEBO is a low-profile, powerful and compact 750 lumen headlamp with 5 light modes, and a one-size-fits-all strap. 5 LIGHT MODES Turbo (750 lumens): 30 second intervals / 85 meters High (250 lumens): 5 hours / 62 meters Medium (80 lumens): 15 hours / 32 meters Low (5 lumens): 60 hours / 10 meters Red (5 lumens): 16 hours / 1 meter OPERATION Top-positioned buttons for power and mode selection ACCESSORIES 4 x AAA batteries One size fits all head strap BATTERIES Powered by 4x AAA Alkaline batteries SPECS Weight: 110g (L) 10.16㎝ X (W) 4.06㎝ X (H) 6.1㎝